title: Immunoassay based on carbon nanotubes-enhanced ELISA for Salmonella enterica serovar Typhimurium.
abstract: Among the methods used to detect pathogenic bacteria, enzyme linked immunosorbent assay (ELISA) is one of the most widely used techniques in routine sample analysis. For Salmonella enterica serovar Typhimurium detection, a typical ELISA yields a sensitivity of 10(6)-10(7)CFU/ml. To enhance the detection sensitivity, single-walled carbon nanotubes (SWCNTs) was employed in this study as a labelling platform for antibody and horseradish peroxidase (HRP) co-immobilizing. With high proteins recovery after the coupling process, the resulting Ab/SWCNTs/HRP bioconjugate was used in the proof-of-concept ELISA experiments. Limit of detection (LOD) was found to be 10(3) and 10(4)CFU/ml for direct and sandwich ELISA, respectively, when Ab/HRP at 1:400 ratio was used. This figure accounts for 1000-time greater in detection sensitivity when compared to a commercial Ab-HRP conjugate. The Ab/SWCNTs/HRP bioconjugate was tested further in real samples and found a superior activity over the commercial Ab-HRP by showing 100-time greater detection limit.
authors.affiliation: School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bang Khun Thian Chai Thale Road, Bang Khun Thian, Bangkok 10150, Thailand.
authors.forename: Wilanee
authors.initials: W
authors.lastname: Chunglok
authors.forename: Dyah Kinasih
authors.initials: DK
authors.lastname: Wuragil
authors.forename: Sukunya
authors.initials: S
authors.lastname: Oaew
authors.forename: Mithran
authors.initials: M
authors.lastname: Somasundrum
authors.forename: Werasak
authors.initials: W
authors.lastname: Surareungchai
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005516:Food Microbiology; D057230:Limit of Detection; D037742:Nanotubes, Carbon / Q000737:chemistry*; D012486:Salmonella typhimurium / Q000302:isolation & purification*
chemical_list: D037742:Nanotubes, Carbon